powerpoint hangs except safe mode

I'm running Office 2007 Beta 2 on Vista Beta 2. Word works (although it seems sluggish to me), but PowerPoint always hangs. It works in Safe Mode, though. Any idea why and how I should troubleshoot this?
Dell Precision M70 Prenium M Proc, 2.13 GHz 2 GB RAM NVIDIA Quadro FX Go 1400 256 MB graphics card
Thanks, Ellen

I have Office 2007 Beta 2 running on Vista Beta 2. Word works (although it seems sluggish to me), but PowerPoint hangs every time. I've tried safe mode, Detect and Repair -- nothing works.
However, when I start Vista in safe mode, it works fine. How do I go about troubleshooting what may be causing the problem? PowerPoint worked fine under XP. I can't think of anything else that I've changed on my computer.
Dell Precision M70 Pentium M 2.13 GHz 2 GB RAM NVIDIA Quadro FX Go1400 256 MB video card
Thanks, Ellen